Note 6 - Business Segments - Information About Reportable Segments (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Sales of products		$ 140,839	$ 179,393	$ 417,662	$ 481,712
Income (loss) from operations		20,942	38,240	40,788	95,422
Greens Creek [Member]
Sales of products		61,061	85,804	191,250	199,260
Income (loss) from operations		16,575	26,498	46,107	49,407
Lucky Friday [Member]
Sales of products	[1]	199	26,140	20,022	70,152
Income (loss) from operations		(4,642)	6,652	(8,974)	13,442
Casa Berardi [Member]
Sales of products		53,990	41,131	139,524	126,614
Income (loss) from operations		2,882	3,691	(1,071)	16,246
San Sebastian [Member]
Sales of products		25,589	26,318	66,866	85,686
Income (loss) from operations		17,017	18,415	42,363	58,911
Other Segments [Member]
Income (loss) from operations		$ (10,890)	$ (17,016)	$ (37,637)	$ (42,584)

[1] The $0.2 million in sales reported for Lucky Friday for the third quarter of 2017 represents gains on base metal derivatives contracts.